Field of the Invention
The invention relates to a floor-supporting configuration in motor vehicles including a front floor crossmember, which extends transversely to the longitudinal axis of the vehicle between two sills extending alongside the vehicle bodywork and which is fixedly connected to the sills. The vehicle bodywork includes two longitudinal members which are disposed between the sills and extend from the front part of the vehicle rearward under a floor panel.
Various embodiments of floor-supporting configurations in motor vehicles are known. For example, Published European Patent Application No. EP 0 602 331 A1 discloses bodywork longitudinal members which are offset in height and extend downward below the floor panel. In order to avoid deformations of the footwell of the passenger cell in the event of a crash, in particular a head-on crash, the longitudinal members have an energy-absorbing member section followed by an easily deformable member section in their upper region.
Furthermore, German Patent No. DE 42 05 891 C2 discloses bifurcating the longitudinal members in the region of the passenger cell. The inner longitudinal member element is spatially close to a central tunnel and the outer longitudinal member element spatially close to a door sill. This measure is intended to increase the strength of the floor assembly and to permit an improved introduction and transmission of force in the event of applications of large forces.
German Patent No. DE 40 29 153 C2, corresponding to U.S. Pat. No. 5,090,774, furthermore discloses a floor assembly with a front crossmember which, for its part, is placed from outside against a floor panel forming a foot slope and is connected to laterally extending sills. Two longitudinal members which are offset in height extend from the front part of the vehicle rearward under the floor panel, but are not connected to the crossmember, which is provided in the region of the floor slope, but rather, are supported on the floor panel and on rear crossmembers which, for their part, are likewise connected to the sills. In the event of a crash, the forces acting on the longitudinal members are to be introduced into the sills, the floor panel and, if appropriate, the central tunnel and are to be absorbed by these components.
Furthermore, Published European Patent Application No. EP 0 693 414 A1, corresponding to U.S. Pat. No. 5,562,329, discloses a body structure of a passenger vehicle which includes an end wall arranged between the front part of the vehicle and the passenger cell. Two front longitudinal members, which are spaced apart from each other, are connected in each case to a floor member, which is situated behind them and proceeds as an extension of the longitudinal members. The body structure further includes lateral outer sills, upright hinge pillars (A-pillars) and a floor. In this case, the two front longitudinal members extend continuously as far as the end wall and are connected to a first crossmember, which is placed onto the outside of the end wall. Level with this crossmember, a second crossmember is arranged on the side facing the passenger cell and is, for its part, connected to the central tunnel and divides on the end side into two hollow members which are arranged one above the other, the upper hollow member section being connected to the end wall and the hinge pillar, and the lower hollow member section being connected to the end wall, the sill and the floor. The intention, as a result, is firstly to provide a stiff passenger cell and secondly to absorb head-on impact forces readily and introduce them over a large surface area via the front longitudinal members into the adjacent body structure.
It has proven disadvantageous that, as a consequence of introducing force into the upper passenger cell regions, namely the hinge pillars and accordingly also into the roof structure, these have to be appropriately configured and dimensioned and stiffened in order to avoid a deformation of the passenger cell in this region.